This request is for supplemental support for nine months for section IIIE (Behavioral Deficits in Stroke Patients) of the clinical research center proposal NS-10828 ("An Interdepatmental Stroke Program"). The supplement is requested to implement more intensive study of deficits in higher cerebral function, aphasia in particular, in the acute phase and serially over the time course of evolution in cases of stroke whose lesion site and etiology are documented by computerized tomogram (CT scan) and confirmed in fatal cases by autopsy. The quantitation of differential features of the aphasic deficit by the behavioral approach to aphasia developed in this laboratory and the invaluable aid provided by CT scanning in estimation of lesion site and size have been combined, and supplemented by traditional aphasia testing, clinical assessment and autopsy-documented literature review to provide potentially significant revision of the expected outcome, anatomic correlation, and mechanisms of Broca's aphasia and thalamic aphasia. Studies are also underway bearing on Wernicke's aphasia, amnestic aphasia, Balint's syndrome, and so-called 'conduction' aphasia. The case load and the rapid evolution of the deficits in individual cases require more intensive and more frequent testing than is currently possible from the funding available. Reliable prediction of the quantitative evolution of a given focal deficit over time is being attempted to provide baseline data against which to evaluate recently developed modes of therapy in acute stroke.